Figure 1 Physiological parameters of P. massoniana seedlings cultivated at various calcium levels . (A) Photographs of plant leaves. (B) Total chlorophyll content. (C) Net photosynthetic rate (Pn). (D) Leaf Ca content. (E) Seedling aerial part dry weight. (F) Soluble protein content. (G) Hydrogen peroxide (H2O2) content. (H) Total APX activity. (I) Total SOD activity. Data are indicated as means ± SE from six replicates.